Subterranean anchor.



PATENTED DEC. 15, 1903.

0. F. PRESLAR.

SUBTERRANEAN ANCHOR.

APPLICATION FILED 0011.21, 1902. V

110 MODEL.

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llivrrnn Srarns Patented December 15, 1903.

Pat ent tribe.

SUBTERRANEAN ANCHOR.

SPECIFICATION forming part of Letters Patent No. 747,219, dated December 1903- Application filed October 21. 1902. Serial No. 128,181. (No model.)

To (11 whom, it may concern:

Be it known that I, CHARLES F. PRESLAR, a citizen of the United States, residing at Oincinnati, in the county of Hamilton and State of Ohio, have invented new and useful Improvements in Subterranean Anchors, of which the following is a Specification.

My invention relates to a device for anchoring the sills or foundations of various structures to the rocky strata of the earth and for kindred purposes, and is especially applicable to securing submarine structures and foundations liable to displacementsuch as light houses, sea-walls,dams, &c.or for anchoring cotter-dams, caissons, &c., whether permanently or temporarily.

For conveniently illustrating my invention 1 may refer to dams, wing-walls, locks, &c., a class of structures Whose foundations are often laid of necessity upon gravel or earthy strata beneath the Water-surface, owing to the depth of the rock-bed.

My invention provides means for securely anchoring the sill (and, if necessary, the entire foundation) to the bed-rock. lying beneath, and is conveniently applicable, within reasonable limits, without regard to the depths or character of the intervening earthy deposits.

My invention is illustrated in the accompanying drawings, in which Figure l is an ideal section showing a timber sill, intervening earthy strata, and bedrock beneath, with an aperture ready for the insertion of the anchor, and to the right thereof an anchor already in position. Fig. 2 is an axial section of the lower end of an anchor rod or bolt, showing the spreader in initial position ready to be lowered to position in the seating-hole of the bed-rock. Figs. 3 and 4. are cross-sections of the anchor in the planes designated at or y of Fig. 2, and Fig. 5 a similar section at plane .2 of Fig. 1; Fig. 6, a slightlymodified form of the anchor and spreader shown in holding position.

Referring'now to the accompanying drawings, A designates a timber sill, resting upon intervening strata B of gravel or other material, and O the stratum of rock beneath, to which it is desirable to anchor the sill A against possible displacement.

In submarine work the ordinary excavation by means of caissons is continued until a suitable resting-place for the sill A is reached, and thence a hole is drilled or drifted downward through the intervening strata B by suitable tools to the solid rock C beneath and carried into the body of the same a sufficient depth to insure the proper holding power for the anchor. Near the bottom the hole thus formed is enlarged, preferably in conical form, as indicated at C, leaving a portion O stillbelow. This enlargement may be made by a suitably-constructed drill, such as I have devised and exhibited in another application for Letters Patent to be filed hereafter. The hole being thus formed and completed a short cylinder 0 termed the anvil,of steelor hard iron, may be lowered intothe lower socket O, and then the anchorrod D, with spreader E, is lowered in the hole 1) until the spreader rests upon the cylinder 0 as indicated in Fig. 2.

The anchor D is a cylindrical or hollow bar, of iron or steel, into the lower end of which (if solid) is drilled an axial aperture d, Figs. 2, 3, 4-, to a height slightly exceeding the total length of the spreader E and cut from side to side across said aperture by two or more radial slits d in axial planes, Figs. 2, 4, to a height corresponding with the conical portion of the spreader E.

The spreader E isablock of metal, preferably in conical form, terminating in a short axial spur or guide e in cylindrical form, corresponding in cross-section with the apertured of the anchor. The conical angle of the spreader corresponds with that of the enlargement c of the aperture (9, formed in the rock 0, and the spur e of the spreader serves the double purpose of a tongue, by which it is attached to the anchor in lowering to position and a centering-guide to maintain its proper relative position thereafter. In lowering to position the spur e is inserted in the lower end of the axial aperture d and held by a small rod or pin 0, which is sheared oil? in driving. The anchor then being lowered into position in the hole I) until the attached spreader E rests upon-the anvil c is then driven downward over the spreader, the segments formed by the slits cl being expanded outward, as indicated in Fig. 5, until they fill the enlargement c, as shown in Figs. 1 and 5, forming a conical head of the anchor in v the space thus prepared to receive it in the solid rock (J, with a rigid engagement. The upper end of the anchor projecting through and above the sill A may be threaded and provided with a nut n or slotted for a wedgekey, or other means of fastening may be used to secure the still A to the anchor.

It will he understood by those skilled .in the art of sinking holes through earthy strata that the depth of strata intervening between the sill A and the bed-rock 0, within reasonable limits, is not material and that the drilling of the bed-rock and the enlargement of the aperture, as described, can be easily ef fected at any reasonable depth and that cores of the rock may be taken from time to time to ascertain its nature and suitability for anchorage. This part of the operation is conducted by toolsand in the manner common in the art of tube-well sinking, and the length of the anchor D will depend upon the depth of the receiving-aperture.

While I have here illustrated the anchor secured to a sill A, yet, as will be readily seen, it may be extended upward through courses of wood, brick, or stone through part or all of a wall.

Among the many applications of the invention the securing of caissons to the bottom of bodies of water may be cited as especially useful Where compressed air is employed to prevent the inflow of water. Suitable anchors may thus be put down and screwed in place from the water-surface and caissons let down between the same and firmly secured thereto against possible flotation, and cofferdams may be secured in like manner. When vno longer needed, the anchor-rods may be every sort of anchorage where a structure is to be fastened to the earth or a superstructure to a stone foundation.

In many cases a stout Wrought-iron pipe may be substituted for the bar-as an anchor.

In securing superstructures to a rock Wall or to a foundation of heavy stone a somewhat simpler form of the anchor maybe used in which the anchor-rod is cut across in one direction onlyand driven over an expanding wedge instead of a cone. This construction is illustrated in Fig. 6.

I claim as my invention and desire to secure by Letters Patent of the United States- The combination with a rock foundation or underlying rocky stratum ofthe earth having therein a hole enlarged at its lower portion, of a wedge and a split rod or tube of metal expanded over said wedge to a holding fit with the enlargement of the receiving-aperture.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit.- nesses.

CHARLES F. PRESLAR. Witnesses:

J os. R. GARDNER, CHAS. IIERBERT J ONES. 

